In fact, if you will have quanta to play a card like Eternity or a Nymph, usually you will have a quanta supply that is enough to cast its skill. And talking about this with these cards... lets see. Flying weapons + Shard or creature + BE + Shard its a 3 card combo, that can be removed by a single spell, like Rewind, or Black Shadow, or Lobotomizer, or anything that kills the creature / animated weapon. Doesnt really seem to be reliable. Nymphs? You really have a lot of a type of Nymph, to make it and Shard in a good deck? Post a strong deck with the Shard, and I can change my mind.
If the Shard had kept the readiness part, it would be interesting because playing a card and using it at same turn is game changing. Not really OP from start. It was OP with Dive. Dive its a skill that its unfair, I think. Any card that increase attack will have an issue with Dive. It could be changed, I think. But even not changing it, the readiness effect shouldnt stack: ready creature, then even more ready, then even more ready, then eve more ready? This would correct the Dive problem. The way the Shard is, we have a rare card that adds almost nothing to the game play, wow, great.
About the free metamorphosis, yes, I have changed mark a lot. But the 100 cost really doesnt hurt me. I just change when the gains are supposed to be bigger. Its still a good thing, but making Scorpio stronger is much more trouble to me than the 100 cost of metamorphosis. If it had changed to "free metamorphosis to every mark you had already used", like the mark type being free after you pay a 100 fee, already good enough. Anyway, Im not complaining about the free metamorphosis. It looks like a small gift, so we are not bored about the rest of the update